PRODUCT DESCRIPTION This solid brass gauge offers a combination of inches and millimeters with notched jaws for taking both internal and external measurements. Capacity 3" (80 mm). Graduations by 1/16ths and 1.0mm. PRODUCT SPECIFICATIONS -. Material: Brass .- Resolution: 001" or 0.1 mm .- Capacity: 3" or 80 mm. .- Units: SAE & Metric .- Graduation: by 1/16ths and 1.0mm.